Reference

Markus Aretz, John Nudds (2003): The holkerian/asbian boundary (visean) at the little asby scarstratotype (Cumbria, England): New evidences on its coral fauna, facies and biostratigraphic zonation – Berichte des Institutes für Geologie und Paläontologie der Karl-Franzens-Universität Graz – 7: 7.